Modifiable risk factors

Oral squamous cell carcinoma (OSCC) is a multifactorialdisease. The main risk factorsare lifestyle, but environment andgenetics play a variable role. Most ofthe lifestyle (modifiable) factors:

Tobacco

All forms of tobacco, both smoked and smokeless, are carcinogenic. Tobacco generates several carcinogens (cancercausing chemicals) and for oral cancer most relevant are the tobacco-specific nitrosamines (TSNAs). These chemicals, from manufactured tobacco , as well as free radicals resulting in alterations in various antioxidant enzymes (glutathione-S-transferase, glutathione reductase, superoxide dismutase, catalase, and glutathione peroxidase), which are mutagenic.

Tobacco contains multiple carcinogens such as:

Tobacco of course also predisposes users to:

Unfortunately, tobacco use is widespread worldwide and increasing in the young and in resource-poor communities.

Alcohol

Alcohol (ethanol) may be carcinogenic via various mechanisms but an important route is by its oxidization to acetaldehyde (a carcinogen) by enzymes (alcohol dehydrogenases; ADHs). Acetaldehyde is then degraded to non-carcinogenic acetate by aldehyde dehydrogenases (ALDH) (fig 1).

Genetic variations in the activities of these enzymes (ADH and ALDH) may thus influence the outcome of exposure to alcohol, and thus its carcinogenicity in any individual. There are also ethnic variations in these enzymes. High ADH activity or low ALDH lead to high acetaldehyde levels with increased carcinogenic potential- though this may be balanced if the associated ‘hangover’ headache dissuades further alcohol ?imbibition.